1、Planning, Designing, and Constructing Fixed Offshore PlatformsWorking Stress DesignAPI RECOMMENDED PRACTICE 2A-WSDTWENTY-SECOND EDITION, NOVEMBER 2014Special NotesAPI publications necessarily address problems of a general nature. With respect to particular circumstances, local,state, and federal law
2、s and regulations should be reviewed.Neither API nor any of APIs employees, subcontractors, consultants, committees, or other assignees make anywarranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of theinformation contained herein, or assu
3、me any liability or responsibility for any use, or the results of such use, of anyinformation or process disclosed in this publication. Neither API nor any of APIs employees, subcontractors,consultants, or other assignees represent that use of this publication would not infringe upon privately owned
4、 rights.API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure theaccuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, orguarantee in connection with this publication and hereby expr
5、essly disclaims any liability or responsibility for loss ordamage resulting from its use or for the violation of any authorities having jurisdiction with which this publication mayconflict.API publications are published to facilitate the broad availability of proven, sound engineering and operatingp
6、ractices. These publications are not intended to obviate the need for applying sound engineering judgmentregarding when and where these publications should be utilized. The formulation and publication of API publicationsis not intended in any way to inhibit anyone from using any other practices.Any
7、manufacturer marking equipment or materials in conformance with the marking requirements of an API standardis solely responsible for complying with all the applicable requirements of that standard. API does not represent,warrant, or guarantee that such products do in fact conform to the applicable A
8、PI standard.All rights reserved. No part of this work may be reproduced, translated, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Se
9、rvices, 1220 L Street, NW, Washington, DC 20005.Copyright 2014 American Petroleum InstituteForewordThis document contains engineering design principles and good practices that have evolved during the developmentof offshore oil resources. Good practice is based on good engineering; therefore, this re
10、commended practice consistsessentially of good engineering recommendations. In no case is any specific recommendation included that could notbe accomplished by presently available techniques and equipment. Consideration is given in all cases to the safety ofpersonnel, compliance with existing regula
11、tions, and antipollution of water bodies. U.S. customary (USC) conversionsof primary metric (SI) units are provided throughout the text of this publication in parentheses, for example, 150 mm(6 in.). Most of the converted values have been rounded for most practical usefulness; however, precise conve
12、rsionshave been used where safety and technical considerations dictate. In case of dispute, the SI units should govern.Offshore technology continues to evolve. In those areas where the committee felt that adequate data were available,specific and detailed recommendations are given. In other areas, g
13、eneral statements are used to indicate thatconsideration should be given to those particular points. Designers are encouraged to utilize all research advancesavailable to them. As offshore knowledge continues to grow, this recommended practice will be revised. It is hopedthat the general statements
14、contained herein will gradually be replaced by detailed recommendations.Reference in this document is made to the 1989 edition of the AISC Specification for Structural Steel BuildingsAllowable Stress Design and Plastic Design. The use of later editions of AISC specifications is specifically notrecom
15、mended for design of offshore platforms. The load and resistance factors in these specifications are based oncalibration with building design practices and may not be applicable to offshore platforms. Research work is now inprogress to incorporate the strength provisions of the new AISC code into of
16、fshore design practices.In this document, reference is made to AWS D1.1/D1.1M:2010, Structural Welding CodeSteel. While use of thisedition is endorsed, the primary intent is that the AWS code be followed for the welding and fabrication of fixed offshoreplatforms. However, where specific guidance is
17、given in this API document, this guidance should take precedence. This edition supersedes the 21st Edition dated December 2000, as well as Errata and Supplement 1 dated December2002, Errata and Supplement 2 dated September 2005, and Errata and Supplement 3 dated October 2007. Revisionbars are not us
18、ed for this edition for clarity because of the extensive document reorganization outlined in theIntroduction.The verbal forms used to express the provisions in this recommended practice are as follows: the term “shall” denotes a minimum requirement in order to conform to the recommended practice, th
19、e term “should” denotes a recommendation or that which is advised but not required in order to conform to therecommended practice, the term “may” is used to express permission or a provision that is optional, the term “can” is used to express possibility or capability.Nothing contained in any API pu
20、blication is to be construed as granting any right, by implication or otherwise, for themanufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anythingcontained in the publication be construed as insuring anyone against liability for infringement of
21、letters patent.This document was produced under API standardization procedures that ensure appropriate notification andparticipation in the developmental process and is designated as an API standard. Questions concerning theinterpretation of the content of this publication or comments and questions
22、concerning the procedures under whichthis publication was developed should be directed in writing to the Director of Standards, American PetroleumInstitute, 1220 L Street, NW, Washington, DC 20005. Requests for permission to reproduce or translate all or any partof the material published herein shou
23、ld also be addressed to the director.iiiGenerally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-timeextension of up to two years may be added to this review cycle. Status of the publication can be ascertained from theAPI Standards Department, tele
24、phone (202) 682-8000. A catalog of API publications and materials is publishedannually by API, 1220 L Street, NW, Washington, DC 20005.Suggested revisions are invited and should be submitted to the Standards Department, API, 1220 L Street, NW,Washington, DC 20005, standardsapi.org.ivContentsPage1 Sc
25、ope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Normative References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26、. . . . . . . . . . . . 13 Terms, Definitions, Acronyms, and Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.1 Terms and Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27、 . . . . . . . . . . . . 23.2 Acronyms and Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28、 . . . . . . . . . . . . . . . . . . . . . . . . 54.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.2 Operational Considerations. . . . . . . . . . . . . . . . . . . . . . . .
29、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.3 Environmental Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.4 Site Investigation-Foundations . . . . . . . . . . . . . . . .
30、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134.5 Selecting the Design Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144.6 Platform Types. . . . . . . . . . . . . . . . . . . . . . . . . . .
31、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164.7 Exposure Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184.8 Platform Reuse . . . . . . . . . . . . .
32、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.9 Platform Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.10 Safety Consider
33、ations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.11 Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34、. . . . 215 Design Criteria and Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35、 . . . . . . . . . . . . . . . 225.2 Loading Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235.3 Design Loads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245.4 Fabrication and Installation Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 Structural Steel Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
37、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 566.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 566.2 Allowable Stresses for Cylindrical Members. . . . . .
38、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576.3 Combined Stresses for Cylindrical Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 636.4 Conical Transitions. . . . . . . . . . . . . . . . . . . . . . . .
39、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 687 Strength of Tubular Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 737.1 Application. . . . . . . . . . . . . . . . . .
40、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 737.2 Design Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 737.3 Simple Joints. . .
41、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 797.4 Overlapping Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
42、 . . 837.5 Grouted Joints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 847.6 Internally Ring-stiffened Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
43、. . . . . . . . . . . . . . 857.7 Cast Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 857.8 Other Circular Joint Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
44、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 857.9 Damaged Joints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867.10 Noncircular Joints. . . . . . . . . . . . . . . . . . . . . . . . . . .
45、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 868 Fatigue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 868.1 Fatigue Design. . . . . . . . . . . .
46、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 868.2 Fatigue Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 868.3 Stress
47、Concentration Factors (SCFs). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 888.4 S-N Curves for All Members and Connections, Except Tubular Connections . . . . . . . . . . . . . . . . . . . . 898.5 S-N Curves for Tubular Connections . . .
48、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 908.6 Fracture Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93vContentsPage9 Foundation Design .
49、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 939.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 939.2 Pile Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 939.3 Pile Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
